A chain of responsibility investigation has been launched against well-known trucking company Lennons Transport Services after police uncovered alleged speed tampering, fatigue breaches and drug possession.

Officers descended on the company's Enfield depot today to conduct a compliance check of its fleet and comb through company records in the wake of a fatal crash involving one of its trucks last month.

Police and road authorities, along with their interstate counterparts, are hunting down trucks currently on the road.

NSW Police says it has found six trucks at the company’s Enfield depot with evidence of speed manipulation tampering and false truck log book entries.

Speaking to Macquarie Radio today, the Commander of the Traffic and Highway Patrol Command, Assistant Commissioner John Hartley, says police believe speed tampering of trucks has been "company sanctioned".

A 33-year-old Lennons B-double driver is accused of crossing an embankment on the Hume Highway last month and ploughing head-on into a car, killing all three occupants.

Police yesterday charged him with three counts of dangerous driving occasioning death.

He is due to appear in Campbelltown Local Court on May 16. His licence has been suspended and police could lay further charges following the outcome of toxicology tests.

Hartley has used the police operation against Lennons to issue a stern warning to trucking companies.

"We are determined to send a clear message to truck operators flouting safety regulations across the state – you will face serious criminal charges," he says.

"Transport companies must follow safe work practices, they have a responsibility to the motorists of NSW."

Hartley says the investigation into Lennons includes taking records and looking at service manuals "to see what responsibility and onus the company owners and directors may have had".

NSW Police says most of the company's fleet has been accounted for.

Officers stopped one of the company’s trucks at Marulan, on the NSW southern tablelands, and allegedly discovered its speed limiter had been tampered with.

The driver of that truck was also allegedly found with cannabis. He has been charged with drug and fatigue-related offences. The man will appear at Goulburn Local Court in March.

Police stopped another truck in Albury and issued its driver with a defect notice for significant brake wear and infringement notices for not complying with oversize permits.

Meanwhile, Victoria Police found one of the company’s trucks abandoned on the side of a road after its driver fled the scene. The log book was found in a nearby rubbish bin. It has been seized as evidence.

NSW Police says examination of the trucks is ongoing. Police are also examining the records and systems maintained by the company.

The work signals the start of a broader chain of responsibility investigation by Roads and Maritime Services into the business practices of the company, NSW Police adds.

Police in Queensland, South Australia and Victoria have been alerted to intercept all trucks within the fleet to check for safety breaches.

The trucks will be stopped and checked while the drivers will be subjected to roadside drug and alcohol testing. Police will also conduct drug dog operations at several of the inspection stations to check the trucks for illegal substances.

A well-known operator, Lennons runs services across the country and counts Toll, TNT and Ikea among its customers.

Managing Director Tony Lennon recently posted a message on the company’s website in reference to the last month's accident.

"As this incident is under investigation by the Police, I am obviously unable to comment on the accident itself but I would like to express our deepest sympathy to the families involved in this very tragic accident," he writes.